let age = 25 //数字类型
let age_string = "25"
// console.log(age == 25)
// console.log(age == 30)
// console.log(age != 30)
// console.log(age > 20)

let name = "David"
// console.log(name == "David")
// console.log(name == "Julia")

//console.log(age === age_string) //字符串类型
//console.log(age !== age_string)

//console.log(age == "25")

let score = "100"
let res = Number(score)

//console.log(res)
//console.log(Number("David"))

let str = String(50)
//console.log(str, typeof str)

let bo = Boolean(100) //true
//console.log(bo, typeof bo)

//数学运算的隐性转换
//console.log(10 + "5") // "105"
//console.log("10" + 5)

console.log(5 == "5") //ture
console.log(5 === "5") //false
console.log(10 > "5") //ture

if("") { //false

}

if(0) { //false

}

if("hello") { // "hello" -> ture
    console.log("hello")
}

